Magneto



P. BROWN ET AL MAGNETO Filed June 2, 1925 INVENTOR ATTORNEYS Patented 2, 192 4.

UNITED STATES.

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' IAGNITO D Application fled June 2,

States, residing at S ringfield, in the county of Hampden and'itate of Massachusetts, have invented new and useful Improvements in Magnetos, of which the following is a specification.

This invention relates to improvements in magnetos and is more particularly concerned with the actuating mechanism thereof.

The general type of magneto, with which n this invention is concerned, is that in which an armature is moved substantially in a straight line path toward and away from,

and preferably into contact with magnetic poles. The general class of actuating mechanism to which this invention relates, is that wherein the driving spring (formov ing the armature away from its poles) is first placed under stress for, the armature driving function by mechanism operated by the engine but is incapable of moving the latter until the contact between the armature and poles has been br0ken -such contact being broken, after the drlvlng spring has been stressed, by an inelastic transmission of force from engine operated parts, after which the driving spring comes into play and drives the armature: away from its poles more rapidly than it would be otherwise driven by the engine.

One example ofa magneto and an actuat ing mechanism of the class above defined will be found in the pending application for United States Letters Patent of Ira E. Hendrickson, Serial No. 504,334, filed September 30, 1921. v

Movement of the armature away from its poles, in the manner and by the mechanism, above described, is important in that the spark is produced. independent of engine speed and an intense spark 1s produced at cranking and low engme speeds. In certain cases, this sort of actuating mechanlsm is not so important when the engine is running at high speed and this invention is concerned with the provision of means whereby either form of operation may be accomplished, when and as desired. The general object of the lIIVGIItIOII 1s to provide, in magneto actuating mechanism of the general type defined, means for rendering the drive spring inoperative, when 1988. Serial 11'0- 843,087.

desired, and for driving the armature 'directly from the engine, asby an inelastic transmission of force therefrom.

Another object of the invention relates to an arrangement. of parts, whereby, when the drive spring is rendered inoperative, the ignition spark is automatically advanced.

Other objects and advantages relate to the particular construction and arrangement of parts and will more particularly a pear in the following description and in t e illustrative embodiment of the invention in the accompanying drawings, in which Fig. 1 is an end elevational view of a mag neto embodying the invention;

Fig. 2 is a front elevational view thereof;

Fig. 3 is an enlarged fragmentary seciii onal plan view taken on the line 3-3 of Fig. 4 is a. cross sectional view the line 4-4 of Fig. 3; i

Fig. 5 is an enlarged fragmentary front elevational View of a portion of Fig. 2;

Fig. 6 is a cross sectional view taken on the line 66 of Fig. 5;

- Fig. 7 is a diagrammatical view of the magneto proper; and

Fig. 8 is a cross sectional view taken on the line 8-8 of Fig. 2.

In these drawings, there is shown, in full detail, an embodiment of the invention which incorporates many desirable features relating to the particular construction and arrangement of various parts, which, although important and preferred, are not necessarily essential in so far as the broader aspects of the invention, as above outlined are concerned. As to the broader aspects of the invention, the showing is to be taken as an illustrative example of one of many embodiments of the invention.

The invention is not particularly concerned with the magneto structure proper but rather with improved actuating mechanism for a magneto of a given type. Accordingly the magneto structure has not been illustrated in. detail and the general type of magneto, with which the invention is concerned, will sufficiently appear from the diagrammatic showing in Fig. 7. The magneto is of the general type in which an armature, such as a, is moved in a substantially straight line path to and from, and preferably into and out of contact with magtaken on nected to the poles of a suitable magnetic source such as the permanent magnet c. The electrical windings are prefera ly, al-

though not necessarily, associated with the cores b and, as Shown, comprise a primary and a secondary coil d and e, respectively, on each core. The two coils d and the two coils e are electrically connected, asin series, as illustrated, and the terminals of the connected coils d are electrically connected to relatively movable breaker points f and g, a condenser It being bridged across the breaker points. The terminals of the connected coils e are suitably connected, as indicated, to the ignition device, such as the spark lug i.

In igs. 1 and 2, the ends of the cores 6 clearly appear and the armature a is shown in contact with them. The members 7' and are parts of the mechanism for operating the movable breaker point g, this action bein accomplished from the armature a, to w ich the member is is fixed. A complete disclosure of the magneto structure in one desirable.and referred form will be found in the pen ing application above identified.

In magnctos of this type, the armature is eriodically caused to move rapidly away rom its poles b and thus cause a substantial change in the flux flowing in the magnetic circuit. The coils d are connected, by breaker points f and g, in a closed electrical circuit at the time when the armature is in contact with its poles. These coils d function to prevent rapid changes in flux in the magnetic circuit and, in effect, hold the flux until the armature has moved a sufiicient distance away from its poles to create a substantial air gap, at which time the breaker points are separated and an ignition current generated in coils e. The points f and g are moved into contact as the armature nears its poles and thereby function to prevent any sudden change of flux whiclr might occasionally cause a small upthrow spark.

The magneto may be suitably supported from the engine in any suitable way, as by the bracket or frame A, from which, as shown, all the actuating mechanism may also be supported, with the exception of the actuating cam or eccentric 10, which is fixed to an engine driven shaft, such as the cam shaft S.

The actuating mechanism embodies a re silient driving means for moving the armature away from its poles, herein shown as a coil spring 11. This spring is stressed at proper intervals by a transmission of force from the engine, as by the movement of eccentric 10, but, even when fullv stressed, this spring is insuflicient of itself toovercome the forces holding armature a to its poles. For overcoming such forces and" starting the armature on its downward flight, a tripping device 1Q is employed which after the spring 11 has been stressed comes into play to remove the armature from its oles by an 'inelastic transmission of force rom engine operated parts, such as the eccentric 10. The actuating mechanism also includes suitable means for returning the armature to its poles, herein shown as includin a coil spring 13. The force acting to hohf the armature to its poles, as herein illustrated, is that due to magnetic attraction.

The actuating mechanism, as above broadly defined, is not a feature of the present invention but rather a definition of the general class of mechanism to which the invention is adapted. The invention, ac cording to one feature, is characterized by the provision of means for renderin the drive spring inoperative when desired and as to a second feature of automatically effecting with the above object an advance in timing. The means for accomplishing both objectseconsists of a member 14 which is movable into position to cooperate with member 12 and prevent the preliminary stressing of the drive spring and cause the armature to be tripped, or started away from its poles,'at an earlier time than it otherwise would be.

The invention, in addition to-the features above described, contemplates the provision of certain advantageous and desirable features, as improvements in armature actuating mechanism of the general class described, which features relate to the particular mechanism illustrated herein. As to the broader featuresof the invention, the details of the particular mechanism, described below, may

e varied with wide limits and still embody the invention.

In conjunction with the armature actuating mechanism two arms 15 and 16 are pivotally mounted intermediate their ends on a common stud 17 carried by frame A. The drive spring 11 is mounted bet-ween the outer ends of these arms and tends to separate them. The tripping device 12 is adjustably secured to one of these arms, as 16, near the same end but in an offset location, as shown in Fig. 1. The return spring 13 acts between a suitable spring seat on the inner end of arm 16 and a stationary spring seat 18 provided on frame A. The inner ends of both arms 15 and 16 lie between the spaced arms 19 of a fork 20 fixedly secured to the lower face of armature a. The inner ends of arms 15 and 16 overlie and underlie. respectively, a stud a fixed on and extending between arms 19. The arm 16 is provided with a recess 21, herein shown as substantially hemi-spherical, and into this recess 'a stud 22, provided with a rounded outer end, ex-tends. This all) stud 22 is fixed to a screw 23 which is threaded into an eccentric strap 24, encompassing the eccentric 1O, whereby the stud is adjustable radiallywith respect to the eccentric. The stud is held in adjusted position by a lock nut 25.

The tripping device 12 is also adwstably mounted, being in the nature of a cap screw threaded into arm 16 and held in adjusted position by a lock nut 26.

The spring 11 is also ad ustable for its lower spring seat 27 is mounted ona; screw 28, threaded into arm 16 and held 1n adjusted position by a lock nut 29.

The device 14 for rendering the drive sprin 11 inoperative is formed as an integral portion of a lever 30 by bending over a portion thereof, as shown in Fig. 4:. The lever 30 is 'pivot-ally held to arm 15 by a cap screw 31, as shown in Fig. 6. In order to releasably hold the lever 30 in either of the two positions which it may assume, arm 15 is provided with two pairs of recesses 32 and 33 in its lower face, as shown in Figs. 5 and 6. A circular disc 34:, loosely encompassing the head of screw. 31 and yield-ingly urged upwardly by the spring 11, has a pair of upturned lugs 35, oppositely located thereon. These lugs 35 pass upwardl through recesses 36 in lever 30 (Fig. 3 and are adapted to enter either pair of recesses 32 or 33. When engaged in the former, as shown, the lever 30 is so held that the device 14 is entirely out of the path of member 12 but when located in the recesses 33, the device 14 directly overlies the member 12.

In operation, with the parts occupying the relative positions shown in the drawings, the eccentric 10 has just commenced to move arm 16 by the pressure of stud 22 thereon. The outer end of arm 16 will travel upwardly and spring 11 will be compressed and thus placed under stress for the armature driving function. The outer end of arm 15 does not, however, immediately move upwardly for although a downward pressurev is brought to bear on armature a, during the compression of spring 11, this pressure is not in excess of the force of magnetic attraction which holds the armature to its poles. It is to be noted that, as the outer end of arm 16 is moved upwardly, its inner end is moved downwardly away from stud s and the return spring 13 is compressed, whereby a path is cleared for the downward flight of armature a.

After spring 11 has been fully stressed the member 12 has been moved into engagement with arm 15 and, on continued rotation of eccentric 10, the arm 15 is. moved and armature a disengaged from its poles. This disengagement, it is to be noted, is effected by an inelastic transmission from the eccenarmature supporting force of magnetic attraction is ver much diminished and continues to diminish at a very rapidly increasing rate, so that almost immediately the force of the stressed spring 11 becomes superior to that of magnetic attraction and the spring expands and moves armature a downwardly more rapidly than it would be moved by member 12. In other words the arm 15 is forced away from member 12-during the downward flight of the armature.

Continued rotation of the eccentric 10 eventually causes stud 22 to move radially inward toward shaft S and thus arm 16 is allowed to move under the force of spring 13, whereby the armature is carried upwardly and again seated on its poles. The stud 22 is free to move in one direction relatively to arm 16 and, in the form illustrated, does move partially out of recess 16.

At such times the spring 13 functions also as a supporting force for armature a but this force, as has been described, is relaxed entirely during the stressing of the drive spring so that magnetic attraction is the only armature supporting force functioning at that time.

The operation, thus far described, has been found useful and advantageous and it is particularly eflective on starting ..or low engine speeds because the armature movement is effected independently of, and at a higher speed than, engine speed. However, on higher engine speeds, a spark of even less intensity than that required for starting, will suflice and. moreover, a more rapid armature speed may then be imparted directly from the engine than at starting. In many cases, direct operation of the armature from the engine during its higher speeds is desired and to permit such operation, the member 14: is swung into overlying relation with member 12. This, as will be evident from Fig. 1, will prevent the stressing of spring 11 in the manner described and will cause the armature to be not only removed but moved during its entire downward flight by an inelastic transmission of force from the eccentric. The two arms 15 and 16 do not then have relative movement on the downward flight of the armature and the latter is, as a practical matter, directly connected to the engine. The return spring 13 functions as formerly to return the armature, this being necessary in the embodiment illustrated, on account of the loose connection of stud 22 with arm 16. It will be noted that the armature a is removed from its poles at an earlier point in the engine cycle than formerly, whereby the spark is automatically advanced as is deslred for hi h speed running. Also it is msured that t e spark is retarded, as it should be, or starting, for unless member 14 is.

moved to the illustrated position, only a small current will be roduced which is rarely sufficient for starting. Consequently, the operator is forced to move the member 14 to the illustrated osition to cause the production of a sufliizient spark to start the engine and, when member 14 is thus moved, the spark is automatically retarded.

The invention has been disclosed herein, in an embodiment at present referred, for the purposes of illustration ut the scope of the invention is defined by the appended claims rather than by the foregoing description.

Claims:

1. In a magneto, a movable armature,

magnetic pole pieces with which said armature cooperates to make and break a magnetic circuit, said armature in one posltion contacting with both pole pieces, a drive spring for moving the armature into posit1on to break said circuit and insufficient even when fully stressed to overcomethe force of magnetic attraction by which the armature is held in the first named position, means operated from the engine to first stress said spring and then break the magnetic hold on the armature by an inelastic transmission of force from the engine, and means for rendering said spring inoperative, when desired.

2. In a magneto, a movable armature, magnetic pole pieces with which said armature cooperates to make and break a mag netic circuit, said armature in one position contacting with both pole pieces, a drive spring for moving the armature into positionto break said circuit and insufficient even when fully stressed to overcome the force of magnetic attraction by which the armature is held in the first named position, means operated from the engine to first stress said spring and then break the magnetic hold on the armature by an inelastic transmission of force from the engine, and means for rendering said spring inoperative, when desired, and causing the armature to be driven from the engine by an inelastic transmission of force therefrom.

3. In a magneto, a movable armature, magnetic pole pieces with which said armature cooperates to make and break a magnetic circuit, said armature in one position contacting with both pole pieces, a drive spring for moving the armature into position to break said circuit and insufficient even when fully stressed to overcome the force of magnetic attraction by which the armature is held in the first named position, means operated from the engine to first stress said spring and then break the magnetic hold on the armature by an inelastic.

spring for moving the armature into position to break said circuit and insufficient even when fully stressed to overcome the force of magnetic attraction by which the armature is held in the first named position, means operated from the engine to first stress said spring and thenbreak the ma netic hold on the armature by an inelastic transmission of force from the engine, and means for rendering said spring inopera tive, when desired, and causing the armatureto be driven from the engine b an inelastic transmission of force therefi'om, said means also arranged to cause the armature to move away from its first named position at an earlier time than when operated by said spring.

5. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, mechanism operated from the engine for moving the armature away from its poles, said mechanism including two relatively movableparts and an interposed spring, and means for preventing relative movement of said parts when desired.

6. In a magneto, ofthe type in which an armature is moved into and out of contact with magnetic poles, mechanism operable from an engine for moving the armature away from its poles, said mechanism including two parts movable the one relatively to the other into engagement and functioning when in engagement to cause a preliminary movement of the armature by an inelastic transmission of force from the engine, a spring associated withsaid parts and stressed by said relative movement and functioning to cause the armature to be rapidly moved after its preliminary movement, and means for rendering said spring inefi'ective to move the armature.

7. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, mechanism operable from an engine for movin the armature away from its poles inclu ing means initially effective by an inelastic transmission of force from the engine and elastic means subsequently effective independently of the engine, and means for rendering the elastic means ineffective when desired.

8. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, mechanism operable arness 9. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, elastic means stressed by the operation of the engine and releasable at properly timed intervals to move the armature away from its poles at a speed independent of engine speed, and mechanism op-- erable when desired to render the first named means inefi'ective and to move the armature away from its polesat speeds dependent on engine speeds.

10. In a magneto, of the type in which an armature is moved into and out of contact With magnetic poles, elastic means stressed by theoperation of the engine and releasable at properly timed intervals to move the armature away from its poles at a speed independent of engine speed, and mechanism operable when desired to render the first named means ineffective and to move the armature away from its poles at speeds dependent on engine speeds, said mechanism including cooperating parts for connecting the armature to the engine and providing "an inelastlc transmission of force therefrom.

11. In a magneto, of the type wherein an armature is moved into and out of contact with magnetic poles, elastic means adapted to move the armature in its flight away from said poles, means for returning the armature to its poles, and means for moving the returning means out of engagement with the armature tic means.

12. In a magneto, of the type wherein an armature is moved into and out of contact with magnetic poles, elastic means adapted to move the armature in its flight away from said poles, means controlled by engine operation to break the magnetic hold between the armature and its poles to permit said elastic means to act, means for returning the armature to itspoles, and means for moving the returning means out of engagement with the armature prior tothe operation of said elastic means. 1

13. In a magneto, of the type wherein an armature is moved into and out of contact with magnetic poles, a pivoted arm adapted to move the armature away from its poles,

prior to the operation of said elasmeans controlled by engine operation for moving said arm on its pivot, and resilient means associated with said arm and adapted to be stressed by the movement of said means before the arm is effective to move the armature.

14. In a magneto, of the type wherein an armature is moved into and out of contact with magnetic poles, a pivoted arm adapted tomove the armature away from its poles, means controlled by engine operation for moving said arm on its pivot, resilient means associated with said arm and adapted to be stressed by the movement of said means before the arm is effective to move the armature, and means for preventing said stressing of the resilient means when desired.

15. In a magneto, of the type in which an armature is moved into ,and out of contact with magnetic poles, an arm pivoted intermediate its ends and having one end adapted to move the armature away from its poles, a member movable by the engine and spaced from the other end of said arm so that it does not immediately engage the latter, a spring interposed between the arm and member and adapted to be stressedon relative movement thereof, and'means for preventing such relative movement, when desired.

16. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, an arm pivoted intermediate its ends and having one end adapted to move the armature away from its poles, a second arm pivoted intermediate its ends and having one and adapted to move the armature toward its poles, a spring connecting the other ends of said arms, and means adapted for operation under the control of an engine for moving said second arm.

17.; In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, an arm pivoted intermediate its ends and having one end adapted to move the armature away from its poles, a second arm pivoted intermediate its ends and having one end adapted to move the armature toward its poles, a spring connecting the other ends of said arms, and an abutment on the other end of one of said arms adapted to engage the other end of the other arm after said spring has been stressed to a predetermined degree by the relative movement of said arms.

18. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, an arm pivoted inter,

mediate its ends and having one end adapted to move the armature away from its poles, a second arm pivoted intermediate its ends and having one end adapted to move the armature toward its poles, a spring connecting the other ends of said arms, an abutment on the other end of one of said arms adapted to engage the other end of the other arm after said spring has been stressed to a predetermined degree by the relative movement of said arms, and means for preventing the relative movement of said arms.

19. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, an arm pivoted intermediate its ends and having one end adapted to move the armature away from its poles, a second arm pivoted intermediate its ends-and having one end adapted to move the aramture toward its poles, a spring connectin the other ends of said arms, means adape for operation under the control of an engine for moving said second arm, and a spring acting on the first named end of the second arm. 4

20. In a magneto, of the type in which an armature is moved into and out of magnetic poles, an arm pivoted intermediate its ends and having one end adapted to move the armature away from its poles, resilient means tendin to move the armature toward its les, an a second arm pivoted interme iate its ends and having one end arranged to act on the other end of the first named arm to cause the armatures to be moved away from. its poles, the other end of the-second named arm arranged to retract said resilient means simultaneously with the actionv of its first named end on the first arm.

V 21. In a-magneto, of the type in which an armature is moved'into and out of contact with magnetic poles, two arms pivoted intermediate their ends on a common axis, said arms at one end arranged to move the arma ture in opposite directions, a spring interposed between the arms at their other ends, and means operable from the engine for causing the movement of one of said arms.

22. In a magneto, of the type in which an" armature is moved into and out of contact with magnetic poles, two arms pivoted intermediate their ends on a common axis, said arms at one end arranged to move the armature in opposite directions, a spring in- -terposed between the arms at their other ends, an abutment on one of said arms adjacent said spring adapted to engage the other arm after the spring has been compressed to a predetermined degree, and

means operable from'the engine for causing the movement of one of said arms.

23. In a magneto, of the t pe in which an armature is moved into an out of contact with magnetic poles, two arms pivoted intermediate their ends on a common axis, said arms at one end ararnged to move the armature in opposite directions, a spring interposed between the arms at their other ends, an abutment on one of said arms adjacent said spring adapted to engage the other arm after the spring has been compressed to a predetermined degree, movable means for extending the height of said abutment when desired, and means operable from the engine for causing the movement of one of said arms.

24:. In a magneto, of the type in which an armature is moved into and out of contact with magnetic poles, two arms pivoted intermediate their ends on a common axis, saidarms at one end arranged to move the armature in opposite directions, a spring interposed between the arms at their other ends, and means operable from the engine for causing the movement of one of said arms in one direction, and resilient means for moving it in the other direction.

25. In combination with an engine and a magneto of the type in which an armature is moved into and out of contact with magnetic poles, mechanism operablefrom theengine and including elastic means for moving the armature away from its poles, and means for rendering said elastic means ineffective when desired and simultaneously advancing the time at which the armature is moved away from its poles.

In testimony whereof we haxe afiixed our signatures.

PHELPS BROWN. IRA E. HENDRIOKSON. 

